The present invention relates to a vehicle seat, and more particularly, to a vehicle seat having a passenger detector.
A vehicle equipped with an air bag is typically provided with a passenger detector, or a load detector. The passenger detector detects whether a passenger is sitting on a seat or the passenger""s weight. The amount of gas generated to inflate the air bag is adjusted in accordance with the detection.
Japanese Unexamined Patent Publication No. 11-1153 describes a detector employing a load cell to detect the weight applied by a vehicle seat. The load cell is located between a rail, which supports the seat, and a mount bracket, which secures the rail to the passenger compartment floor.
Japanese Unexamined Patent Publication No. 11-1154 describes a detector employing a link unit to detect the load applied to a seat cushion. The link unit is located between the seat cushion and a frame, which supports the seat cushion. The link unit is pivoted in accordance with the load of the seat cushion. The load detector detects the seat load based on the position of the link unit.
Japanese Unexamined Patent Publication NO. 11-94637 also describes a detector employing a link unit to detect the load applied to a seat cushion. The link unit is located between a slide rail and the seat cushion. The load detector detects the seat load based on the position of the link unit.
However, the conventional load detectors are complicated and large. Further, the accuracy of the conventional load detectors is relatively low.
Generally, the retaining force produced by a seat belt acts on the seat. This may result in the load detector inaccurately detecting the passenger""s weight. Further, when a child safety seat is mounted on the vehicle seat, a large load is applied to the vehicle seat. Thus, a load detector that is not affected by the restraining force of a seat belt has been sought after.
It is an object of the present invention to provide a vehicle seat having a simple and highly accurate passenger detector.
To achieve the above object, the present invention provides a vehicle seat including a seat cushion and a load detector for detecting the load applied to the seat cushion. The load detector includes a sensor bracket having a deformation portion, which is deformed in accordance with the degree of the load. A strain sensor is arranged on the deformation portion to detect the degree of deformation of the deformation portion. A force limiter bracket is adjacent to the sensor bracket to limit deformation of the deformation portion within a predetermined range. An anchor bracket is formed integrally with the force limiter bracket. The anchor bracket is attached to a seat belt.
A further aspect of the present invention provides a vehicle seat arranged on an upper support that moves along a lower support, which is fixed to the floor of a passenger compartment. The seat includes a seat cushion, a seat frame for supporting the seat cushion, and a load detector arranged between the upper support and the seat frame to detect the load applied to the seat cushion. The load detector includes a sensor bracket having a deformation portion, which is deformed in accordance with the degree of the load, and first and second connecting holes. A strain sensor is arranged on the deformation portion to detect deformation of the deformation portion. A force limiter bracket is located adjacent to the sensor bracket. The force limiter bracket has a fastening hole and a restricting hole. The force limiter bracket limits deformation of the deformation portion within a predetermined range. A first bolt is fitted in the first connecting hole and the restricting hole to fix the sensor bracket to the seat frame. A second bolt is fitted in the second connecting hole and the fastening hole to fix the second bracket to the upper support. An anchor bracket is formed integrally with the force limiter bracket and attached to a seat belt.
Another aspect of the present invention provides a load detector arranged between a vehicle seat and the floor of a passenger compartment to detect the load applied to the seat. The load detector includes a sensor bracket having a deformation portion, which is deformed in accordance with the degree of the load, and first and second connecting holes. A strain sensor is arranged on the deformation portion to detect deformation of the deformation portion. A force limiter bracket is located adjacent to the sensor bracket. The force limiter bracket has a fastening hole aligned with the force connecting hole and a restricting hole aligned with the second connecting hole. The force limiter bracket limits deformation of the deformation portion within a predetermined range. An anchor bracket is formed integrally with the force limiter bracket and attached to a seat belt.
Other aspects and advantages of the present invention will become apparent from the following description, taken in conjunction with the accompanying drawings, illustrating by way of example the principles of the invention.